title: Serum magnesium concentration in children with functional constipation treated with magnesium oxide.
abstract: OBJECTIVE
  To determine whether hypermagnesemia recently reported in adult patients possibly develops in children with functional constipation taking daily magnesium oxide.
  
  
  METHODS
  We enrolled 120 patients (57 male and 63 female) aged 1-14 years old (median: 4.7 years) with functional constipation from 13 hospitals and two private clinics. All patients fulfilled the Rome III criteria for functional constipation and were treated with daily oral magnesium oxide for at least 1 mo. The median treatment dose was 600 (500-800) mg/d. Patients were assessed by an interview and laboratory examination to determine possible hypermagnesemia. Serum magnesium concentration was also measured in sex- and age-matched control subjects (n = 38).
  
  
  RESULTS
  In the constipation group, serum magnesium concentration [2.4 (2.3-2.5) mg/dL, median and interquartile range] was significantly greater than that of the control group [2.2 (2.0-2.2) mg/dL] (P < 0.001). The highest value was 3.2 mg/dL. Renal magnesium clearance was significantly increased in the constipation group. Serum magnesium concentration in the constipation group decreased significantly with age (P < 0.01). There was no significant correlation between the serum level of magnesium and the duration of treatment with magnesium oxide or the daily dose. None of the patients had side effects associated with hypermagnesemia.
  
  
  CONCLUSIONS
  Serum magnesium concentration increased significantly, but not critically, after daily treatment with magnesium oxide in constipated children with normal renal function.
authors.affiliation: Department of Pediatrics, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Tatsuki
authors.forename: Reiko
authors.initials: R
authors.lastname: Miyazawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tomomasa
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishige
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Arakawa
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003248:Constipation / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007223:Infant; D054368:Laxatives / Q000627:therapeutic use*; D008274:Magnesium / Q000097:blood*; D008277:Magnesium Oxide / Q000627:therapeutic use*; D008297:Male
chemical_list: D054368:Laxatives; D008277:Magnesium Oxide; D008274:Magnesium